Deduplicate code in map observers

[addisoncrump]

Nearly all of the MapObserver implementations seem to be copy/pasted, and there is a lot of old code that is no longer needed. Duplicated code should be extracted to common methods where >5 lines.

[sarthakvyas16]

i will work on this issue please assign me this issue.

[domenukk]

We don't really assign issues, but feel free to work on it. Thanks! :)

[domenukk]

Depends on the quality of your PRs and you proposal

[tokatoka]

this turned out to be impossible because Deref didn't work?